Path: utzoo!attcan!uunet!microsoft!jimad
From: jimad@microsoft.UUCP (Jim ADCOCK)
Newsgroups: comp.std.c++
Subject: Re: Packing, Ordering, and Rearranging
Message-ID: <57858@microsoft.UUCP>
Date: 1 Oct 90 18:56:49 GMT
References: <1407@lupine.NCD.COM> <2218@ux.acs.umn.edu> <57467@microsoft.UUCP> <1990Sep21.130531.7437@zorch.SF-Bay.ORG> <57650@microsoft.UUCP> <57681@microsoft.UUCP> <2311@ux.acs.umn.edu>
Reply-To: jimad@microsoft.UUCP (Jim ADCOCK)
Organization: Microsoft Corp., Redmond WA
Lines: 20

In article <2311@ux.acs.umn.edu| hopper@ux.acs.umn.edu (Eric Hopper) writes:

|	I also think that the default method of member ordering should be
|changed, it would cause confusion, and may make older code harder to port.
|So I think that a 'packed' keyword ought to be added to the C++ language.

Exactly what packing would this keyword imply, and also what object model
would it imply?

|	I think Kent made a very good point earlier when he said that
|currently popular languages all allow you to have a fair amount of precise
|control over the machine beneath the language. If C++ turns into a 'school'
|language in which you are not allowed control over such things as structure
|member placement I think we'll see a loss of popularity, and portability.

Reading the ANSI-C spec, I do not see any promises of the "precise" control
being referred to.  I see instead, great latitude provided to compiler
writers in order to allow efficient code be generated on a given machine.
Perhaps you can clarify what constraints provided by the ANSI-C spec meet
your ideas of "precise control" ?